1. Field of the Invention
The present invention relates in general to shift control devices for automatic transmissions for automotive vehicles and more particularly to a parking lock mechanism for a gate type automatic transmission shift control device.
2. Description of the Related Art
A parking lock mechanism in an automatic transmission shift control device prevents a shift lever from being shifted from a parking position into any other gear positions unless a brake pedal is depressed after start of an engine in order to prevent sudden start of an automotive vehicle. More specifically, the parking lock mechanism includes a lock lever which is swingable when actuated by an actuator in responsive to depression of the brake pedal. When the shift lever is in the parking position, the lock lever prevents a position pin in contact with a detent cutout portion from being pushed down for thereby preventing the shift lever from being shifted from the parking position into any other gear positions. In such a shift control device, the shift lever moves along a linear shift groove so as to be shifted into one of gear positions of P (Parking), R (Reverse), N (Neutral), D (Drive) and L (Low).
A gate type automatic transmission shift control device in which a shift lever moves along a gate opening having a crank-like shape, is disclosed for example in Japanese Patent Provisional Publication No. 8-334167. In this shift control device, a lock lever is swingably supported on a housing which is formed with a gate opening. The shift lever has a radial projection which is capable of abutting upon the lock lever. When the shift lever is shifted into a parking (P) position, the projection is caused to abut upon the lock lever to disable shift of the shift lever from the parking position into a parking lock released position. In this instance, the lock lever in contact with the projection of the shift lever is urged against the side wall of the housing, so that the side wall serves as a bearing or support member.